Radio apparatus



Feb. 22, 1938.

3v, anunnnnlllim I R. W. MCDONALD RADIO APPARATUS Filed May 8, 1937 JF VV. McimJa/d Patented Feb. 22, 1938 PATENT OFFICE 2,109,431 RADIO APPARATUS Raymond W.

Washington, D. 0. Application May 8,

1 Claim.

The invention forming the subject matter of this application relates to sound producing cabinets; and, particularly to cabinets adapted to house radio receiving sets, electric phonographs and the like.

This invention is particularly adapted for use in radio apparatus including a loud speaker, and a receiving set mounted in the same cabinet; and has for its principal object the provision of a mount for the loud speaker, whereby the transmission sound vibrations from the speaker to the receiving set is practically eliminated.

Another object of the invention is to provide a sound producing cabinet with a baflle board pivoted about a substantially horizontal axis to direct the sounds emanating from the cabinet at any desired angle with respect to a horizontal plane.

' A further object of the invention, is to provide a supporting base for the receiver cabinet as a whole, whereby the cabinet may be rotated about a substantially vertical axis.

In the drawing:

Figure 1 is a perspective view of one form of the invention as embodied in a radio receiver;

Figure 2 is a sectional elevation illustrating a means for angularly adjusting a baffle board mount for the loud speaker;

Figure 3 is a horizontal section taken on the line 33 of Figure 2;

Figure 4 is a detail of a means for mounting the cabinet for rotation about a substantially vertical axis.

Referring to the several figures, a baflie-board 30 is hinged to swing about its upper edge on the front wall of the cabinet 3| In this construction the baffle-board comprises the frame 32 covered by the usual screen 33, and having the transverse brace 34 secured to the top and bottom of the frame 30 to form a support for the loud speaker 35. Side plates 36 and 31 are secured to the opposite sides of the frame 32. The side plate 31 has an arcuate rack 38 suitably secured thereto. This rack is in mesh with the spur gear 39 fixed on the inner end of a shaft 40 which is journaled Mcdonald, signor of one-half to Washington, D. 0., as- Cecil David Kaufmann,

1931, Serial No. 141,550

in a bracket 4| suitably secured to the side wall of the cabinet. The shaft 40 projects through this side wall and has a knob 42 fixed to its outer end to facilitate manual adjustment of the shaft 40 for the purpose of giving the battle-board 30 the desired inclination, with respect to the front wall of the cabinet.

This invention is designed, not only to determine the direction of the vibrations with respect to horizontal emanating from the cabinet, but is also designed to determine the direction of these vibrations with respect to any vertical plane. For this purpose the cabinet as a whole is mounted to rotate about a substantially vertical axis on the base plate 43, which is provided at its center with an aperture for the pivot bolt 44, extending through the bottom of the cabinet. The upper face of the base plate 44 and the bottom wall 45 of the cabinet may be provided with the cooperating race elements 46 and 41 of a ball bearing to decrease the friction between the base and the cabinet. The adjustment of the baflle-board about a horizontal axis, and that of the cabinet about a vertical axis provide a universal adjustment for projecting the sound waves in any desired direction.

What I claim is:

In acoustic apparatus, a cabinet having an opening in one wall thereof, a balile board normally fitting in said opening hinged at one edge to said wall to swing outwardly with respect to said wall whereby said bafile board is altogether outside of said cabinet in all angular positions of swing, wings at the lateral edges of said bafile board and movable therewith, closing the angle between said bafile board and cabinet in any position of swing of said baffle board, forming extensions of the sounding box constituted by said cabinet, means for adjusting the baflle board at any desired angle, and a sound producer mounted on the inner side of said baffle board and movable therewith.

RAYMOND W. MCDONALD. 

